WritePathToXml

代码说明：

说明：  使用C#进行xml的读写。根据输入的路径，搜索路径下的所有文件和子文件夹，将这些文件和子文件夹的路径保存到xml中。(Use C # to read and write xml. According to the input path, all files and subfolders under the path are searched, and the paths of these files and subfolders are saved into xml.)